Two men climbing a granite rock wall known as El Capitan in Yosemite National Park fell to their deaths Saturday morning, the National Park Service said.
The agency said Jason Wells, 46, of Boulder, Colo., and Tim Klien, 42, of Palmdale, Calif., fell from the Freeblast climbing route and did not survive the fall.
Park rangers received calls at 8:15 Saturday morning and responded along with search and rescue staff.
Both were reportedly highly experienced climbers.
The Freeblast route is one of the lower sections of the 3,000-foot granite wall.
Climbing.com reports that the two men were roped together when they fell 1,000 feet.
"Tim told me that Jason was the strongest and best partner he ever climbed with," a friend, Wayne Willoughby, told the website, which spelled Tim's last name as Klein.
Rangers are still investigating the cause of the accident.
The pair had climbed El Capitan several times together, and began regularly climbing together while they were in college in San Diego, the website reports.